Bridges, AngusYacoot, AndrewKissinger, ThomasTatam, Ralph P.2022-01-182022-01-182021-12-06Bridges A, Yacoot A, Kissinger T, Tatam RP. (2022) Multiple intensity reference interferometry for the correction of sub-fringe displacement non-linearities, Measurement Science and Technology, Volume 33, Issue 2, February 2022, Article number 0252010957-0233https://doi.org/10.1088/1361-6501/ac3aadhttps://dspace.lib.cranfield.ac.uk/handle/1826/17422Displacement measuring interferometers, commonly employed for traceable measurements at the nanoscale, suffer from non-linearities in the measured displacement that limit the achievable measurement uncertainty for microscopic displacements. Two closely related novel non-linearity correction methodologies are presented here that allow for the correction of non-linearities in cases where the displacement covers much less than a full optical fringe. Both corrections have been shown, under ideal conditions, to be capable of reducing all residual non-linearity harmonics to below the 10 pm level.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/interferometrynon-linearitydimensional metrologyArticle1361-6501